1) Dr. Bashir actor Alexander Siddig was the first choice to play Benjamin Sisko

Producer Rick Berman saw Siddig playing King Feisal in the British television production A Dangerous Man: Lawrence After Arabia, and decided to cast him as Commander Sisko. Berman changed his mind when he realized Siddig was only in his mid-twenties, and instead offered him the part of Dr. Bashir — who was originally named Dr. Julian Amoros. This was a part with way less job security: for the first two years Siddig was on the show, the network was constantly telling Berman and the other producers to fire him, because he was the most unpopular character. But the producers held their ground, because they wanted to change Bashir over time and slowly make him more likable. Also: Siddig and Miles O'Brien actor Colm Meaney fought in real life, while their characters were fighting on the show — they had hours of "furious fights" about England and Ireland, according to Siddig.

Also, during the first season, a huge earthquake struck L.A. while Shimerman and Odo actor Rene Auberjonois were in makeup — both actors decided to skip the two hours of makeup removal and go home to check on their families, terrifying many passersby on their way home.

I had heard that story ages ago, the be fair, Odo does look like a building fell on his face.

1) Dr. Bashir actor Alexander Siddig was the first choice to play Benjamin Sisko

Producer Rick Berman saw Siddig playing King Feisal in the British television production A Dangerous Man: Lawrence After Arabia, and decided to cast him as Commander Sisko. Berman changed his mind when he realized Siddig was only in his mid-twenties, and instead offered him the part of Dr. Bashir — who was originally named Dr. Julian Amoros. This was a part with way less job security: for the first two years Siddig was on the show, the network was constantly telling Berman and the other producers to fire him, because he was the most unpopular character. But the producers held their ground, because they wanted to change Bashir over time and slowly make him more likable. Also: Siddig and Miles O'Brien actor Colm Meaney fought in real life, while their characters were fighting on the show — they had hours of "furious fights" about England and Ireland, according to Siddig.

Haha I like that last part.

"Don't underestimate the power of technobabble: the Federation can win anything﻿ with the sheer force of bullshit"

Ronald D. Moore says he kept pitching a musical episode, over and over. His idea was that: "There's just some tech virus that infects the crew and they can only communicate in song, you know? And just do it! And have a ball." Moore pushed for this idea over and over, and "they fought against it and fought against it and fought against it."